Bonding Spa Water

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FionaZuppa

FionaZuppa

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AZ
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Part Time Electrician (semi retired, old) - EE retired.
are there any UL listed stainless fitting (2" f/f npt) that can be used for bonding? i have a manufactured spa that does not technically bond the water to anything. i also have a in-ground cooling system made of PVC. i was thinking of bonding the water by inserting a metal coupling in the PVC line. a UL listed item would be best way. i can get a 2" stainless f/f npt coupling and then i could TIG a stainless threaded rod to the coupling so i can attach a wire to, but it would not be UL listed.

and as a side Q, if i am going beyond requirements can i use non-UL items? as example, my spa is UL listed, so if i wanted to do my own bonding of the water would a non-UL fabricated coupling be ok?
 
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If the spa is UL listed, one would presume it met the bonding requirements that UL demanded at the time of its listing. If you're still interested in going above and beyond, what about using your 2" SS coupler, and a listed ground clamp for 2" pipe? Land your bonding wire on that clamp.

http://www.garvinindustries.com/con...ps/gcb125200?gclid=CIfZ74a7scACFQdcfgodubcAtA

The clamp is UL listed for bonding; I'm not sure any coupler in ever is UL listed for anything.

Personally, I like the stud TIG'ed to the coupler and a lug bolted to it. Functionally, I suppose it really doesn't make a difference. If you decide to go the welded stud route, make sure to remove the heat tint from the inside of the coupler after welding to restore the corrosion-resistant properties of the stainless steel.


SceneryDriver
 
How about a listed pipe grounding clamp for 2" pipe that you put on a SS 2" pipe nipple? I used a 2" pipe ground clamp to bond my copper drain pipes. The pool had a light so the water got bonded that way.
 
i posed the question the way i did because pool parts and what-not are sometimes special for pool installations, like finding odd PVC manifolds vs making own using T's, etc.

the 2" pipe clamp is one option. but in context of "not a requirement" would use of non-UL item be permitted? TIG'ing 1/4-20 ss stud would just make things a tad neater/cleaner, etc. also, clamping does have corrosion issues, and in cases of pipe clamps there are more than one mating area of dissimilar metals (clamp to pipe, and then wire to clamp). welding stud eliminates one of those, etc.
 
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FionaZuppa said:
are there any UL listed stainless fitting (2" f/f npt) that can be used for bonding? i have a manufactured spa that does not technically bond the water to anything. i also have a in-ground cooling system made of PVC. i was thinking of bonding the water by inserting a metal coupling in the PVC line. a UL listed item would be best way. i can get a 2" stainless f/f npt coupling and then i could TIG a stainless threaded rod to the coupling so i can attach a wire to, but it would not be UL listed.

and as a side Q, if i am going beyond requirements can i use non-UL items? as example, my spa is UL listed, so if i wanted to do my own bonding of the water would a non-UL fabricated coupling be ok?
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As long as you are not modifying the listed assembly I don't see a requirement.

I was looking for the requirement for the connection to be cad welder as in 250.8(A)(4) but I am not seeing supply piping as one of the items needing bonding per 680.26(B)1-7. If it's not a 'bonding jumper' then your attachment is not limited to be one of the bonding methods in 250.8 and only needs to be 'connected' per 250.4(A)(4).
 
starbolin said:
As long as you are not modifying the listed assembly I don't see a requirement.

I was looking for the requirement for the connection to be cad welder as in 250.8(A)(4) but I am not seeing supply piping as one of the items needing bonding per 680.26(B)1-7. If it's not a 'bonding jumper' then your attachment is not limited to be one of the bonding methods in 250.8 and only needs to be 'connected' per 250.4(A)(4).
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it is for the purpose of bonding/grounding of the spa water, however, the spa itself is already UL listed so as-is i really dont need to do anything, but i want to add extra safety, etc.
 
FionaZuppa said:
it is for the purpose of bonding/grounding of the spa water, however, the spa itself is already UL listed so as-is i really dont need to do anything, but i want to add extra safety, etc.
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I really don't see a need for it if the unit is listed. Why do you say the water is not bonded? I would imagine there is something in the unit that does bond the water.
 
Dennis Alwon said:
I really don't see a need for it if the unit is listed. Why do you say the water is not bonded? I would imagine there is something in the unit that does bond the water.
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i asked LA Spas, they told me the water wasnt bonded. i think i need to call them again.
 
FionaZuppa said:
i asked LA Spas, they told me the water wasnt bonded. i think i need to call them again.
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well, it seems a case of misunderstanding. the water does pass through a metal housing (heater) and that housing is tied to service ground.

that said:
1) should i bond other items to spa chassis and then tie to gnd spike?
2) given the spa is UL listed, would it be allowed for me to use a non-UL rated fitting to attach bonding wire to (if i did that)?

thanks.
 
Tying to a ground spike is pointless. If you have a equipotential bonding grid around the spa, it would need to be connected to that. Usually in a spa, there is some point to attach your equipotential bonding grid to (could be a lug on the pump). They need to tie all the metal components together somehow internally, so that conductor should be made available to any external bonding the site requires.

Don't know the answer to question 2.
 
kent,
well yes, the area around the spa will have wire mesh and that too will be tied to gnd spike, along with spa chassis.

the point of gnd spikes, at least in my minds, is to provide gnd path to earth for any stray voltage that may show up. a bonded equi-pot isolated circuit can still leave that circuit with voltage on it with potential (probability) that one could still bridge the equi-pot to say earth gnd.

i guess what i am saying is, i am tying things together like you would doing std equi-pot protection, and then tying that to gnd spikes.

i have 50A non-gfci in service panel, 100ft run to a disco, that loops into a distro panel (50A gfci and two 20A gfi branch). the distro panel itself has bare service feed gnd tied to it inside, i then have the panel tied to a gnd spike. the 50A feeds the spa, spa is UL listed, i'll add surface mesh and tie mesh and chassis to 2nd gnd spike, and then both gnd spikes are tied together using another #6 bare copper.

this should, for all intensive purposes, bring all the metal in/around spa to earth potential (making it very hard for anyone to bridge a diff in potential by touching anything metal around the spa). a lifting of poco neutral should cause gfi to trip.

did i get it right ?
 
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FionaZuppa said:
kent,
well yes, the area around the spa will have wire mesh and that too will be tied to gnd spike, along with spa chassis.

the point of gnd spikes, at least in my minds, is to provide gnd path to earth for any stray voltage that may show up. a bonded equi-pot isolated circuit can still leave that circuit with voltage on it with potential (probability) that one could still bridge the equi-pot to say earth gnd.

i guess what i am saying is, i am tying things together like you would doing std equi-pot protection, and then tying that to gnd spikes.

i have 50A non-gfci in service panel, 100ft run to a disco, that loops into a distro panel (50A gfci and two 20A gfi branch). the distro panel itself has bare service feed gnd tied to it inside, i then have the panel tied to a gnd spike. the 50A feeds the spa, spa is UL listed, i'll add surface mesh and tie mesh and chassis to 2nd gnd spike, and then both gnd spikes are tied together using another #6 bare copper.

this should, for all intensive purposes, bring all the metal in/around spa to earth potential (making it very hard for anyone to bridge a diff in potential by touching anything metal around the spa). a lifting of poco neutral should cause gfi to trip.

did i get it right ?
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Is this "distro" panel remote from the structure with the service equipment? If so you do need a grounding electrode at the separate structure. Unless you are on 2005 NEC or earlier you also need separate equipment grounding conductor run with the feeder and the GEC would need connected to the equipment ground instead of the neutral.

At the spa there is nothing prohibiting using ground rods, but there is no requirement to use them either. You do need an equipotential bonding system, however if all conditions in 680.42(B) are met you don't need to install an equipotential bonding system. (2011 did not say this in initial print but a TIA was later added that gave all the conditions that are in the 2014)

A GFCI will not trip if the service neutral is lost it will only trip when there is current imbalance between monitored conductors, loss of service neutral may effect voltages seen and current flow, but will not result in any unbalanced current seen by the GFCI.
 
i believe my town folks marked the permit with "2011 NEC". but yes, the disco & distro are located ~90ft away from my service panel.
 
There is a TIA for the 2011 NEC however if your area did not adopt it then you may not have that luxury. It may depend on when the TIA came out in relation to when your area accepted the 2011NEC
 
FionaZuppa said:
i believe my town folks marked the permit with "2011 NEC". but yes, the disco & distro are located ~90ft away from my service panel.
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90 feet away in same structure or 90 feet away at a different structure is what I was trying to ask?

If at a different structure then a grounding electrode system is required for the separate structure and that is required before we even get into art 680 requirements.
 
kwired said:
90 feet away in same structure or 90 feet away at a different structure is what I was trying to ask?

If at a different structure then a grounding electrode system is required for the separate structure and that is required before we even get into art 680 requirements.
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ah, i see your Q, nope, the feeder basically sticks up out of the ground near spa, this is where a disco and distro are (they are two boxes back-to-back). other than the power coming up from a trench, all of the electric (feed to disco/distro & distro to spa) are in the ground.
 
As has been speculated in other threads, if the spa is on, for example, a concrete patio that extends from the house walls, it would not be a separate structure. But if it in the open, standing alone, it might be a separate structure needing its own ground electrode.
 
FionaZuppa said:
ah, i see your Q, nope, the feeder basically sticks up out of the ground near spa, this is where a disco and distro are (they are two boxes back-to-back). other than the power coming up from a trench, all of the electric (feed to disco/distro & distro to spa) are in the ground.
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As GD mentions, that would be considered a separate structure most places and a grounding electrode system at the separate structure would be required for this application. If you had the SPA only it would be a single branch circuit and be an exception but you have a distribution panel and multiple circuits - this rules out using the exception.This is in 250.32(A).

What this means to your application - since it is a separate structure your ground "spike" (rod) you mentioned earlier in the thread is likely required if there is no other electrodes - and most likely a second rod is required, see 250.53(A)(2). This grounding electrode is not required for the SPA it is required because you have a feeder supplying a separate structure. Put the same panel on the side of the house and run a single circuit to the spa and you no longer have a feeder supplying a separate structure and the grounding electrode requirement changes even though you otherwise have nearly the same installation.

Getting back to your original question which I think has been answered - bonding the water. Most likely your spa has the water bonded, if anything it is done just by having a grounded metal section of piping at the heater location, which is pretty common.
 
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